geeksprogrammings: c#

Showing posts with label c#. Show all posts

Wednesday, 6 July 2016

Object Pooling in Csharp

21:47 Posted by heemanshu bhalla No Comments

What is Object Pooling in Csharp ?

Object Pooling is Technique for Efficient Resource Allocation.A Performance Optimization Technique that is based on using Pool of Pre-Allocated Resources Such of Objects For Efficient Resource Allocation . It refers to Reusing of Allocated Memory again and again instead of demanding for more memory as there are chances that more required memory may be not available at runtime (In Running Application)

Why We Need Object Pooling & How It Works?

Have you Heard about Car Pooling ? Let me tell you about that . Car Pooling and Object Pooling is based on Same Concept .

Both are based on Re-using / Proper Utilization of Resource . Instead of Having or using new Resource Each Time We Require .

In Car Pooling We Use Same Resource Car for Multiple Person Instead of Using Car for Each Person . If 4 Person are going to office instead of going from their own car . Car Pooling Tells to Use one car For all 4 People That will save various Natural Resource and money .

Similarly In Object Pooling Memory is assigned to Program Execution and When more objects are required to initialized then instead of demanding and getting more memory resources it waits for previous memory block to get free to be used .

Didn't Got it Don't Worry See Below

Real Time Example of Object Pooling ?

Problem :

Let’s assume we are running an application which needs allocation of memory for its execution and this application is using Multithreading. This means more than one threads can allocate the same amount of memory simultaneously .

Consider that the application needs 100K memory for its execution and there are 50 threads running simultaneously. All 50 threads will call a method of the application simultaneously.

All the threads will try to allocate 100000 bytes in the heap simultaneously. The OS may not get enough time to swap pages. Thus the application will be under heavy concurrent access, and the application may fail due to misleading memory management!

Solution :

WE can also create a pool of large Memory Block as much we can according to how much memory we require, at startup. That way, say we create 100 times 100K bytes in memory at startup. If it fails, well enough - we know that right at startup! So there is no surprise at runtime, when the application is live! So we can reduce that number to 75 (from 100) and try again to start our application. Once up and running, we know that there will be barely a need for it to allocate more memory at runtime, as we already have the memory for 75 or 100 arrays allocated. It just uses that as "an object pool", pulls from it, and when done, returns the byte arrays for subsequent use. Chances are that unless truly "concurrent", the already allocated byte arrays will be re-used over and over again, and at runtime, no extra memory will be allocated. If all 75 or 100 arrays are in use, and a 101st request comes in, it will need to allocate an additional memory of only one array - which is easy for the OS to manipulate in RAM.

Still Din't Got Don't Worry Feel Free! To Comment

Monday, 23 May 2016

Abstract Class vs interface in Csharp

05:00 Posted by Unknown No Comments

Abstract Class

Abstract Class is a class that is used as a base class and contains common methods that can be defined by class that inherits from this Base Class . We can only inherit abstract class But We cannot instantiate Abstract Class . Abstrac classes contains both incomplete & complete methods . Means it can contains functions with definitions as well as abstract methods with only declarations . It can also contains Data Members along with subs , propreties and methods .

Interface :
Interfaces Contains only Declaration / Signature of Functions and does not contains definition of functions . Unlike Abstract classes Interfaces cannot contain complete methods or methods with definition it only contains signature of methods means only declarations
Interface also supports multiple inheritance that is not supported by Abstract classes

Difference Between Abstract Class and Interface -

Abstract Class
1. Abstract Class Can Contain Complete (functions with definitions) or Incomplete(Abstract) Members
2. Abstract Class cannot be instantiated
3. Abstract Class Can contain Data members
4. Abstract Class Can have Constructors . We Can Have Parameterized Constructors also in Abstract Class

Example :-

public abstract class ABC
{

int _a;
   
  //Parameterized Abstract Class Constructor
  public ABC(int a)
  {
    _a = a;

   }

  //Default Constructor
  public ABC()
  {
   // Code Logic

   }




public abstract void computeA();

};

public class Foo : ABC
{
    // Always pass 123 to the base class constructor
    public Foo() : base(123)
    {
    }
}

5. Incomplete members of Abstract class Means Abstract Members are Virtual Means it can be overridden by Derived Members
6. Abstract Members Cannot be Static
7. Complete Members Can be Static
8. Abstract Members can use Access Specifiers

All Private , Protected and Public Access Specifiers can be used with Abstract Class Methods . Purpose of Create Private Methods in Abstract Class is similar to normal class . These methods are used by other public methods of Abstract class as we know we can also define methods in abstract class.

Interface
1. Interface Can only Contain only Incomplete Methods that means methods with only Declaration without any definition
2. Interface cannot be Instantiated
3. Interface cannot contain data members
4. Interface cannot have constructors
5. there is no virtual member in interface as we cannot provide definition of member function in interface only inheriting class can define that function
6. Interace Cannot have Static Members
7. Complete Member does not exist in Interface
8. Interface member are public and we cannot set any access modifier to interface members

Sunday, 22 May 2016

Difference Between Generic and Collections in C#

00:55 Posted by Unknown No Comments

Difference Between Array - Generic - Collections in Csharp

Array :

An Array is Fixed Size Data Type . For Storing data in Array you need to define the size of array and Also Type of Array ( int, string , float etc )

Depending on Memory Allocation Data Types are of Two Types -

Value Type
Reference Type

See Difference Between Value Type and Reference Type in Link Below -
http://geeksprogrammings.blogspot.in/2015/09/value-types-vs-reference-types-dotnet.html

Array is a Value Type that needs to define its size in order to allocate space to it in memory . This is little problem with array as sometimes we need Dynamic Size to store large number of values

Collections :
Collections are Defined in System.Collections Namespace . Collections Are Variable Sized . We Can add / remove items from collection with any restriction of defining size and type of data

Example :- Arraylist are Collections .

Logically Collections are Referency Types . Now Question is Why Collections are Referencec Types ?

Collections are of Variables Sized So Whenever Some Type is Variable Sized It needs to be stored in head instead of Memory Stack give to application . and poiter to that heap is set in the top of stack . it is stored in heap because main memory is valuable and we don't exactly know that How much size variable sized Collection will take so it is allocated disk space as heap instead of storing it directly in main memory Pointer to heap location is set to top of stack so whenever we require it we can use that pointer to get / set that value .

See Difference Between Value Type and Reference Type ( Stack & Heap ) in Link Below -
http://geeksprogrammings.blogspot.in/2015/09/value-types-vs-reference-types-dotnet.html

Example of Collections -

ArrayList arrList = new ArrayList();
arrList.Add(007);
arrList.Add("Heemanshu Bhalla");
arrList.Add(DateTime.Now);

If we want to loop that arrList then we can do it as below -

foreach (object o in arrList)
{

}

But there is one problem we always need to parse each element in collection using object as we don't know the type of data that it contains and that could create problem on runtime

Problem With Collections & Evolution of Generics

Generic Types Solves This problem check Generic Types Below -

Generic Types :
Generic Types Contained in System.Collections.Generic Namespace . It removes the problem of Unknown Data types exist in Collections

Generic List ( List <T> ) , Here T means datatype that could be Int , String , DateTime etc . So We can define the type of data that we want to store and we can also parse the data simple as type is already known . SO it is Type Safe . If you Create Int Generic List or Generic Type and try to store some different type then it will give compilation Error and does not allow you to store data of Another Type that is not allowed .

Example of Generic List below -

List<string> lstString = new List<string>();
lstString.Add("Heemanshu Bhalla");
lstString.Add("I am A Geek");

List<int> lstInt = new List<int>();
lstInt.Add(007);
lstInt.Add(786);

Friday, 1 May 2015

Using Report Viewer with Dataset Asp.net Csharp and vb

12:42 Posted by Unknown No Comments

For Using Report Viewer in Asp.net or Desktop Application using Csharp or Visual basic I am today providing a simple step by step solution -

Demo File is also available to Download so that you can have a demo for how to use or Use Reports With Dataset in Asp.net . I have provided Both Csharp and Vb code

Step 1 - First of Start a C# Project or Vb Project and then Add an Empty Webform to it .

Step 2 :- Now Right Click on Solution in Solution Explorer and Click on Add then click on New Item . Then Click On DataSet and Give a Name and Click Ok . This will add a Dataset in your Project . I will recommend it give dataset a name similar to database table whose data you want to show in Report Viewer